1. Field of the Invention
The present invention relates to an apparatus and a method for automatically loading a fuel pellet for manufacturing a nuclear fuel rod, and more particularly, to an apparatus and a method for automatically loading a fuel pellet for manufacturing a nuclear fuel rod by automatically calculating a required number of fuel pellets according to a length of a cladding tube.
2. Description of the Related Art
A nuclear reactor is an apparatus for artificially controlling a fission chain reaction of a fissile material to use thermal energy generated during a fission reaction as power.
Generally, enriched uranium in which a percentage of uranium-235 is increased to 2-5 percentage is used in a light water nuclear reactor and, in order to process the uranium into a nuclear fuel to be used in the nuclear reactor, a molding process is performed on the uranium to produce a cylindrical fuel pellet of about 5 g weight.
The fuel pellet that is molding processed as above is dried in a furnace, charged in a cladding tube that is manufactured in a special alloy of a tube shape having a good corrosion resistance, and sealed to be manufactured as a nuclear fuel rod. The manufactured nuclear fuel rod is composed of a bundled fuel assembly and loaded to a core of the nuclear reactor so that combustion occurs through a nuclear reaction.
Although variations may exist depending on a type of the nuclear fuel, the fuel pellet is typically manufactured into a cylindrical shape having a diameter of approximately 8 mm and a height of approximately 10 mm. Therefore, a nuclear fuel rod having a length of about 4 m may contain about 400 fuel pellets charged therein.
In addition, the fuel assembly consists of approximately several hundred fuel rods, and thus, in order to produce one fuel assembly, tens of thousands of the fuel pellets need to be charged in the cladding tube and manufactured into the nuclear fuel rod.
However, the fuel pellets may have a deviation in length to a certain degree during the molding process, and a length of the cladding tube is significantly greater than a length of a unit pellet. Therefore, due to accumulated variation of the length of the fuel pellet, the number of the fuel pellets that are charged in the cladding tube is not constant but varied.
Therefore, the deviation in length of the fuel pellet generated in a fuel pellet manufacturing process creates difficulty in implementing an automated process for automatically charging the fuel pellet in the cladding tube, and a manual operation is performed to determine a required number of the fuel pellets according to a charging length of the cladding tube.